Osman announced the independence of his own small principality from the Seljuk Sultanate of Rum in July 1299, and was acclaimed the Khan of the Kayihan tribe.

The Ottoman principality was just one of many small Turkish principalities in Anatolia at the time that emerged after the dissolution of the Seljuks, all of which the Ottomans would eventually conquer to reunite Anatolia under Turkish rule. The westward drive of the Mongol invasions had pushed scores of Muslims toward Osman's principality, a power base that Osman was quick to consolidate. As the Byzantine Empire declined, the Ottoman Empire rose to take its place.